Now that you know which script to use, how do you record it? Depending on your budget and the resources available to you, you can record the script yourself, use a text-to-speech program, or hire a professional voice actor to record your greeting.
To create or change outgoing voicemail messages for individual extensions or for a Ring Group (multiple extensions).

If you are ready to record your voicemail greeting, you should already have a solid script. Whether you include your mission statement, some fun personal details, or a favorite quote, making your voicemail greeting personal is a great way to set your business apart. Write down what you're going to say, but try to avoid reading it verbatim as you record, or it may start sounding robotic and rehearsed. When listening to your voicemail greetings your callers shouldn't feel like they're listening to an impersonal recording. Keep it conversational. If you need help achieving that conversational tone, check out these tips.
A name recording is the most basic way to personalize your voicemail box. It inserts your name into the default unavailable greeting: “The person at mailbox [four-digit voicemail box number] is unavailable. Please leave your message after the tone. When done, hang up or press the pound key.” Dial *98 on your OnSIP-registered phone. Enter your voicemail box number. Enter the PIN/password for your voicemail box. Press 0 for voicemail box options. Press 2 to record your name. Default Unavailable Greeting